Numerous pharmaceutical or perfumery products are offered in ampoules, the volume of which corresponds with one exact dose for use. In particular ampoules of glass, called single-tipped, of the type shown in FIG. 1 of the accompanying drawings are known. Such ampoules are currently produced by drawing and blowing a blob of glass. Such ampoules can be filled under vacuum in an airtight enclosure by presenting them in large batches, upside down with the drawn-out tip 1 dipping into the liquid. By creating a vacuum in the enclosure the ampoules are emptied of air, and by re-establishing atmospheric pressure the liquid rises into all the ampoules at once; they may then be withdrawn without risk of emptying because the passage in the tip is sufficiently small for atmospheric pressure to prevent the liquid from running out. The ampoules are next flame-sealed in order to shut off the orifice at the end of the tip. This technique enables very high filling rates and the sealing is a quarantee of origin to the user. In use, the tip is broken at the neck 2 which opens an orifice of sufficient area to enable the liquid to run out freely, with air entering to take the place of the liquid. Unfortunately, these glass ampoules are fragile. In addition, for products intended for use by the general public, the need to break the glass tip creates a fear of being cut, with the result that this method of presentation is not always appreciated by the customer.
Ampoules of plastic materials have therefore been devised the handling of which by the user no longer presents any risk of being cut. But such plastic ampoules, which are obtained by moulding, necessarily have an orifice of relatively large area which prevents their filling under vacuum. One is therefore obliged to fill them one by one and then to fit a stopper. This stopper is often tamperproof, that is to say, it can not be removed from the ampoule without special equipment or without the removal being visually apparent. Opening by the user is generally effected by tearing off a portion the ouline of which is weakened in the construction of the stopper itself. So the user has the same guarantees of origin with the glass ampoules. Here again the area of the orifice opened by tearing is sufficient to enable the liquid contained in the ampoule to run out freely. With present plastic ampoules, filling rates are considerably poorer than for glass ampoules with vacuum filling, and the necessity of stoppering the ampoules after filling further increases the cost of the overall filling operation and the overall price of the packaging.